/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.beans.factory.support;

import java.security.AccessControlContext;
import java.security.AccessController;

import org.springframework.lang.Nullable;

/**
 * Simple {@link SecurityContextProvider} implementation.
 *
 * @author Costin Leau
 * @since 3.0
 */
public class SimpleSecurityContextProvider implements SecurityContextProvider {

    @Nullable
    private final AccessControlContext acc;


    /**
     * Construct a new {@code SimpleSecurityContextProvider} instance.
     * <p>The security context will be retrieved on each call from the current
     * thread.
     */
    public SimpleSecurityContextProvider() {
        this(null);
    }

    /**
     * Construct a new {@code SimpleSecurityContextProvider} instance.
     * <p>If the given control context is null, the security context will be
     * retrieved on each call from the current thread.
     *
     * @param acc access control context (can be {@code null})
     * @see AccessController#getContext()
     */
    public SimpleSecurityContextProvider(@Nullable AccessControlContext acc) {
        this.acc = acc;
    }


    @Override
    public AccessControlContext getAccessControlContext() {
        return (this.acc != null ? acc : AccessController.getContext());
    }

}
